Multipurpose therapeutic face mask

ABSTRACT

A therapeutic face mask comprises a face-engaging portion and a single connector having a mask-engaging end and a single treatment-receiving end which has a single attachment mounting for detachably sealingly receiving a treatment attachment, such as an oxygen reservoir bag or a nebulizer. A one-way inhalation valve in the connector permits fluid flow from the treatment-receiving end to the mask-engaging end during inhalation and inhibits fluid flow in the other direction. The mask also includes a valve-governed exhalation port and an anti-asphyxia valve assembly configured to permit fluid flow from ambient to the face-engaging portion during inhalation only when inspiratory effort during inhalation exceeds fluid flow to the treatment-receiving end of the connector. Also provided is an oxygen reservoir bag having a neck shaped for removable coupling to a mating connector of a therapeutic face mask. An oxygen reservoir bag may have a metered-dose inhaler port defined in its neck.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.61/045,304 filed on Apr. 16, 2008, entitled “Oxygen Therapy Face Mask”,the teachings of which are hereby incorporated by reference in theirentirety.

FIELD OF INVENTION

The invention relates to therapeutic face masks, and more particularlyto a therapeutic face mask which can be selectively configured to supplya patient with oxygen from a pressurized source thereof, and to supply apatient with medication.

BACKGROUND OF THE INVENTION

There are various medical conditions which require a patient to besupplied with oxygen, either as pure oxygen or mixed with ambient air ina required ratio. It may also be necessary to supply medication to apatient's mouth without removing the face mask. Further, it may also benecessary to filter ambient air supplied to the patient, for example ifthe ambient air is likely to contain a virus or bacteria which may beharmful to the patient. It may also be necessary to filter air beingexhaled by the patient before it is released to the atmosphere, forexample if the patient has a medical condition which may result in avirus or bacteria being exhaled and likely to harm a person nearby.

Generally speaking, in the prior art various different types of maskshave been used to address some of the above issues.

Where a patient is to be supplied with pure oxygen, or oxygen mixed withambient air in a high oxygen/air ratio, a first type of mask is used, asshown in FIG. 1A. As shown in FIG. 1A, the prior art oxygen therapy facemask 10A comprises a face-engaging portion 12A made from a flexiblematerial, a flexible, airtight bag member 36A permanently secured to theface-engaging portion 12A (i.e. the bag member 36A is not meant to beseparated from the face-engaging portion 12A). More particularly, thebag member 36A is permanently secured by tape 15A to a neck 14A, whichin turn is securely snap fit in a tubular member 16A extending from andintegrally formed as part of the face-engaging portion 12A, and isnon-removable (i.e. the neck 14A is not intended to be withdrawn fromthe tubular member 16A and the snap-fit assembly strongly resistsremoval). A tube attachment member 18A for coupling with a tube (notshown) from an oxygen or oxygen/air source (not shown) extends laterallyfrom the neck 14A and is in fluid communication therewith, and hence isalso in fluid communication with the face-engaging portion 12A and thebag member 36A. Fluid communication between the neck 14A and theface-engaging portion 12A is governed by a one-way valve (the locationof which is denoted by 20A) carried by the neck 14A, which permits fluidto flow from the neck 14A into the face-engaging portion 12A, but whichsubstantially inhibits fluid flow from the face-engaging portion 12Ainto the neck 14A. The face-engaging portion 12A includes exhalationports 22A each comprising a plurality of apertures 23A, which mayinclude diaphragms 24A so that the exhalation ports 22A are one-wayvalves which inhibit the ingress of ambient air, or may consist solelyof the exhalation apertures 23A. In operation, oxygen or an oxygen/airmix is supplied from a tube connected to a pressurized source of oxygen(or oxygen/air mixture), and passes through the tube attachment member18A into the neck 14A. If the patient is exhaling, the one-way valve at20A will be closed, and oxygen (or oxygen/air mixture) is forced totravel into the bag member 36A, which inflates. When the patientinhales, a vacuum is created within the face-engaging portion 12A, whichdraws oxygen (or an oxygen/air mix) from the bag member 36A and/or thetube attachment member 18A through the neck 14A and the one-way valve20A into the face-engaging portion 12A. When the patient exhales, theone-way valve 20A inhibits the exhaled air from passing into the neck14A, so the exhaled air escapes through the exhalation ports 22A.

One problem associated with the type of oxygen therapy face mask shownin FIG. 1A where the exhalation ports 22A are one-way valves is that, inthe event that the oxygen or oxygen/air supply into the tube attachmentmember 18A ceases (e.g. because the tank is empty), there is a risk thatthe patent may suffocate. While known anti-asphyxiation valves may beused to address this issue, this adds cost to the mask, and may haveother drawbacks depending on the type of anti-asphyxiation valve used.In practice, this has led to medical staff disabling at least one of theone-way valves governing the exhalation ports 22A, as has been shown inFIG. 1A. While this post-manufacturing modification assists inpreventing asphyxiation, it also allows the patient to breathe ambientair instead of the desired oxygen or oxygen/air mix. In addition, thistype of mask does not support the periodic administration of inhaledmedication.

A second type of mask, shown in FIG. 1B, is used to provide patientswith oxygen support in lower concentrations (relative to the amount ofoxygen with which the oxygen therapy face mask 10A shown in FIG. 1A isused). This second type of oxygen therapy face mask is shown generallyat 10B, and comprises a face-engaging portion 12B, and a neck 14Bsecured (e.g. by a snap-fit) to the face-engaging portion 12B in fluidcommunication therewith, with no intervening valve. The neck 14B issecurely snap-fit in a tubular member 16B extending from, and integrallyformed as part of, the face-engaging portion 12B, and is non-removable(i.e. the neck 14B is not intended to be withdrawn from the tubularmember 16B and the snap-fit assembly strongly resists removal). The neck14B terminates in a tube attachment member 18B in fluid communicationwith the neck 14B. A plurality of air inlet apertures 21B are defined inthe neck 14B, typically arranged about the base of the tube attachmentmember 18B, and additional exhalation ports 22B, each comprising aplurality of exhalation apertures 23B, are disposed in the sides of theface-engaging portion 12B. The exhalation ports 22A may consist solelyof the exhalation apertures 23A, or may include diaphragm members (notshown) so that the exhalation ports 22B operate as one-way valves toinhibit the ingress of ambient air. In operation, where the exhalationports 22B operate as one-way valves, a patient would inhale ambient airthrough the air inlet apertures 21B, and oxygen or an oxygen/air mixreceived from a tube (not shown) attached to the tube attachment member18B. When the patient exhales, the exhaled air leaves the face-engagingportion primarily through the exhalation apertures 22B, as well asthrough the air inlet apertures 21B. Where the exhalation apertures 22Bconsist solely of the exhalation apertures 23B, both inhaled and exhaledair will pass through both the exhalation apertures 23B and the airinlet apertures 21B. Thus, omission or removal of the one-way valvesfrom the exhalation apertures 23B assists in preventing asphyxiation inthe event of cessation of oxygen (or oxygen/air mixture) supply from thetube (not shown) to the tube attachment member 18B ceases where the airinlet apertures 22B (which are intended to supplement the flow from thetube) are not large enough to provide enough air for respiration. Aswith the first type of oxygen therapy mask 10A, this second type ofoxygen therapy mask 10B does not support the periodic administration ofinhaled medication.

A third type of mask, which is used to support the administration ofinhaled medication, is shown in FIG. 1C. The medication administrationmask shown in FIG. 1C is denoted generally by the reference numeral 10C,and includes a face-engaging portion 12C and a neck 14C in fluidcommunication with the face-engaging portion 12C, with no interveningvalve. The neck 14C is securely snap-fit in a tubular member 16Cextending from, and integrally formed as part of, the face-engagingportion 12C, and is non-removable (i.e. the neck 14C is not intended tobe withdrawn from the tubular member 16C and the snap-fit assemblystrongly resists removal). The neck 14C is adapted to removably receivea nebulizer 80C, by way of a tubular member 88C extending from the cap84C of the nebulizer. Specifically, the tubular member 88C is frictionfit inside the neck 14C. The nebulizer 80C includes a medication cup 82Cwhich contains a volume of liquid medication and is connected by a tubeattachment member (not shown) to a tube 86C coupled to a source of airpressure which cooperates with the internal structure 90C of thenebulizer 80C to atomize the liquid medication for inhalation. Thepatient can then inhale the medication through the neck 14C. Two largeexhalation apertures 23C permit the patient to inhale ambient air, andpermit exhaled air to escape the face-engaging portion 12C of the mask.These exhalation apertures also permit the atomized medication to escapeinto the ambient atmosphere, which is potentially wasteful of expensivemedications. In addition, the exhalation apertures also result inundesirable exposure of the health care workers (and others in theimmediate environment) to the atomized medication.

A further problem arises when a patient requires more than one type oftreatment, such as pure oxygen (or oxygen mixed with ambient air in ahigh oxygen/ambient air ratio) and inhaled medication, or lowerconcentrations of oxygen as well as inhaled medication. In suchsituations, it is necessary to replace the oxygen supply mask, such asthe mask 10A or 10B, with a medication supply mask, such as themedication supply mask 10C, in order to administer the medication, andthen replace the medication supply mask with the oxygen supply mask.This undermines one of the purposes or benefits of using a mask, namelythe isolation of the patient from the ambient atmosphere.

SUMMARY OF THE INVENTION

In one aspect, the present invention is directed to a therapeutic facemask. The therapeutic face mask comprises a face-engaging portion havinga fluid aperture, and only a single connector. The connector has amask-engaging end and a only a single treatment-receiving end, anddefines a fluid passageway between the mask-engaging end and thetreatment-receiving end. The mask-engaging end of the connector iscoupled to the face-engaging portion in fluid communication with thefluid aperture, and the connector has only a single attachment mountingfor detachably sealingly receiving a treatment attachment in fluidcommunication therewith. The attachment mounting is defined at thetreatment-receiving end of the connector. The connector has at least oneinhalation valve interposed in the fluid passageway between themask-engaging end and the treatment-receiving end thereof. Eachinhalation valve is a one-way valve oriented to permit fluid flow fromthe treatment-receiving end to the mask-engaging end during inhalationand to inhibit fluid flow from the mask-engaging end to thetreatment-receiving end. The therapeutic face mask also includes atleast one an anti-asphyxia valve assembly configured to permit fluidflow therethrough from ambient to the face-engaging portion duringinhalation only when fluid flow to the treatment-receiving end of theconnector is less than inspiratory effort during inhalation. Inaddition, the therapeutic face mask includes at least one valve-governedexhalation port in fluid communication with the face-engaging portion.Each valve-governed exhalation port is positioned to define anexhalation path from the face-engaging portion to ambient which bypassesthe inhalation valve and which permits fluid flow from the face-engagingportion to ambient during exhalation and inhibits fluid flow fromambient to the face engaging portion at least when fluid flow to thetreatment-receiving end of the connector exceeds inspiratory effortduring inhalation.

In one embodiment, a single exhalation port is defined in a side wall ofthe connector and is in fluid communication with the face-engagingportion by way of the fluid passageway.

In one embodiment, each exhalation port is defined in the connector andis in fluid communication with the face-engaging portion by way of thefluid passageway, and is positioned between the inhalation valve and themask-engaging end of the connector. Each exhalation port may have afilter mounting for detachably sealingly receiving a filter assembly.

In one embodiment, each anti-asphyxia valve assembly is associated witha corresponding exhalation port. Each anti-asphyxia valve assembly maycomprise a single anti-asphyxia valve disposed in the correspondingexhalation port and oriented to permit fluid flow from the connector toambient through the exhalation port during exhalation, and to permitfluid flow from ambient to the connector through the exhalation portduring inhalation only when fluid flow to the treatment-receiving end ofthe connector is less than inspiratory effort during inhalation.

In one embodiment, each anti-asphyxia valve comprises an aperture havinga single cross member extending thereacross, and a flexible diaphragmsecured to the cross member on an outer side of the cross memberrelative to the fluid passageway.

In another embodiment, the connector includes a valve assembly. In thisembodiment, the connector comprises first and second passages, and thevalve assembly. The first passage is adjacent the mask-engaging end ofthe connector, from which first passage fluid can flow into theface-engaging portion and which can also receive fluid from an interiorof the face-engaging portion, and the second passage is adjacent thetreatment-receiving end of the connector. The valve assembly comprises asingle inhalation valve, the exhalation port, and the anti-asphyxiavalve assembly. The inhalation valve is associated with the firstpassage and the second passage, and is operable to permit fluid flowfrom the second passage to the first passage and inhibit fluid flow fromthe first passage to the second passage. The exhalation port includes aone-way exhalation valve associated with the first passage and operableto permit fluid flow from the first passage to ambient and to inhibitfluid flow from ambient to the first passage. The anti-asphyxia valveassembly includes a one-way anti-asphyxia valve associated with thefirst passage and operable to inhibit fluid flow from the first passageto ambient and to permit fluid flow from ambient to the first passagewhen fluid flow into the second passage is less than inspiratory effortduring inhalation. The inhalation valve comprises a disk-like diaphragmlocated between the first and second passages and movable between openand closed positions, and one of the exhalation valve and theanti-asphyxia valve comprises an annular diaphragm surrounding thedisk-like diaphragm of the inhalation valve and movable between open andclosed positions. The exhalation port comprises at least one apertureclosable by the exhalation valve.

The therapeutic face mask may further comprise an annular filter havinga central aperture. The annular filter is positioned in the valveassembly to filter fluid flow from the first passage through theexhalation port to ambient, and permit unfiltered fluid flow from thesecond passage to the first passage through the central aperture.

A therapeutic face mask according to an aspect of the present inventionmay further comprise an oxygen reservoir bag detachably secured to thetreatment-receiving end of the connector, or a medication supplyingnebulizer detachably secured to the treatment-receiving end of theconnector.

The present invention is also directed to connectors for therapeuticface masks, as described above.

In another aspect, the present invention is directed to a method ofpreparing a therapeutic face mask configured for oxygen administrationfor administration of inhaled medication to a patient while theface-engaging portion is engaged with the patient's face. The methodcomprises the step of removing from the therapeutic face mask an oxygenreservoir bag that is detachably secured to the therapeutic face mask influid communication with a face-engaging portion of the therapeutic facemask, while the face-engaging portion remains engaged with the patient'sface and a filter associated with the therapeutic face mask filters airexhaled by the patient. The method also comprises the step of detachablysecuring a nebulizer to the therapeutic face mask in place of the oxygenreservoir bag so that the nebulizer is in fluid communication with theface-engaging portion of the therapeutic face mask while theface-engaging portion remains engaged with the patient's face and thefilter associated with the therapeutic face mask filters air exhaled bythe patient.

In still another aspect, the present invention is directed to a methodof preparing a therapeutic face mask configured for administration ofinhaled medication to a patient for oxygen administration while theface-engaging portion is engaged with the patient's face. The methodcomprises the step of removing from the therapeutic face mask anebulizer that is detachably secured to the therapeutic face mask influid communication with a face-engaging portion of the therapeutic facemask, while the face-engaging portion remains engaged with the patient'sface and a filter associated with the therapeutic face mask filters airexhaled by the patient. The method further comprises the step ofdetachably securing an oxygen reservoir bag to the therapeutic face maskin place of the nebulizer so that the oxygen reservoir bag is in fluidcommunication with the face-engaging portion of the therapeutic facemask while the face-engaging portion remains engaged with the patient'sface and the filter associated with the therapeutic face mask filtersair exhaled by the patient.

The above-described methods may be carried out using the above-describedtherapeutic face masks.

In another aspect, the present invention is directed to an oxygenreservoir bag. The oxygen reservoir bag comprises a flexible oxygenreservoir bag member, and a valveless neck having a tube attachmentmember in fluid communication with an interior volume of the neck. Theoxygen reservoir bag member is sealingly secured to a lower end portionof the neck so that an interior volume of the oxygen reservoir bagmember is in fluid communication with the interior volume of the neck,and the neck is shaped for removable coupling of an open upper endportion thereof to and in fluid communication with a mating connector ofa therapeutic face mask.

In still another aspect, the present invention is directed to an oxygentherapy face mask. The oxygen therapy face mask comprises aface-engaging portion having an inlet passage through which oxygen froma pressurized source can be received, and a valve assembly connected tothe inlet passage. The valve assembly has a first one-way valve operableto permit flow of oxygen from a source thereof to a patient and inhibitflow in the opposite direction, also has an inlet/outlet passage with atwo-way valve permitting ambient air to flow to the patient andpermitting exhaled air to flow from the patient to the ambientatmosphere.

In one embodiment, the valve assembly has a first tubular inlet portionto which an oxygen reservoir bag may be detachably connected. The firsttubular inlet portion is also capable of detachably receiving, in theabsence of the oxygen reservoir bag, a medication supplying nebulizer,whereby medication can be supplied by the nebulizer through the one-wayvalve into the face-engaging portion for passage to the patient.

In one embodiment, the inlet/outlet passage has a tubular portionconnecting the two-way valve with the ambient atmosphere. The tubularportion is capable of detachably receiving a filter assembly operable tofilter air passing from the ambient atmosphere to the two-way valve andfrom the two-way valve to the ambient atmosphere.

In one embodiment, the two-way valve comprises a rod-like support memberextending across the inlet/outlet passage and a diaphragm mounted on thesupport member and having a closed position blocking air flow throughthe inlet/outlet valve. The diaphragm is bendable by air pressure fromeither side thereof to enable air to flow through the valve from thehigher pressure side of the diaphragm to the lower pressure sidethereof.

In a yet further aspect, the present invention is directed to an oxygenreservoir bag. The oxygen reservoir bag comprises a flexible oxygenreservoir bag member, and a neck having an open upper portion endportion and a tube attachment member in fluid communication with aninterior volume of the neck. The oxygen reservoir bag member issealingly secured to a lower end portion of the neck so that an interiorvolume of the oxygen reservoir bag member is in fluid communication withthe interior volume of the neck. A metered dose inhaler port is definedin the neck. The metered dose inhaler port comprises an inner channeldefined in the neck in fluid communication with the interior volume ofthe neck, and an outer channel defined in the neck in fluidcommunication with ambient. The inner and outer channels are in fluidcommunication with one another, and the outer channel is larger than theinner channel to define a shoulder between the inner and outer channel.The inner channel is angled toward the oxygen reservoir bag member.

In one embodiment, the neck is valveless and is shaped for removablecoupling of the bag to a mating connector of a therapeutic face mask.

In an embodiment, the inner channel and the outer channel arecylindrical and are coaxial with one another, so that the shoulder is anannular shoulder.

DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example,with reference to the accompanying drawings, of which:

FIG. 1A is a perspective view of a prior art oxygen therapy face maskused to administer pure oxygen or a high oxygen ratio oxygen/airmixture;

FIG. 1B is a perspective view of a prior art oxygen therapy face maskused to administer an oxygen/air mixture;

FIG. 1C is a perspective view of a prior art nebulizer face mask used toadminister nebulized medication;

FIG. 2 is a sectional side view, partly in perspective, of a firstexemplary therapeutic face mask in accordance with an aspect of thepresent invention;

FIG. 2A is a view of a one-way valve of the therapeutic face mask ofFIG. 2, taken in the direction of arrow A in FIG. 2;

FIG. 2B is a view of a two-way valve of the therapeutic face mask ofFIG. 2, taken in the direction of arrow B in FIG. 2;

FIG. 2C is a sectional side view, partly in perspective, of thetherapeutic face mask of FIG. 2, showing a detachably mountable filterassembly detached therefrom;

FIG. 3 is an enlarged view of a portion of FIG. 2, showing the one-wayand two-way valves with related structure;

FIG. 4 is an exploded view of the main components of the therapeuticface mask of FIG. 2;

FIG. 5A shows a first exemplary oxygen reservoir bag according to anaspect of the present invention, detachably secured to the therapeuticface mask of FIG. 2;

FIG. 5B shows a first exemplary oxygen reservoir bag according to anaspect of the present invention, detached from the therapeutic face maskof FIG. 2;

FIG. 6A shows a first exemplary nebulizer according to an aspect of thepresent invention, detachably secured to the therapeutic face mask ofFIG. 2;

FIG. 6B shows a first exemplary nebulizer according to an aspect of thepresent invention, detached from the therapeutic face mask of FIG. 2;

FIG. 7 is a flow chart depicting an exemplary method of preparing atherapeutic face mask that is configured for administration of oxygen toa patient, for administration of inhaled medication to the patient,while the face-engaging portion of the therapeutic face mask is engagedwith the patient's face, according to an aspect of the presentinvention;

FIG. 8 is a flow chart depicting an exemplary method of preparing atherapeutic face mask, configured for administration of inhaledmedication to a patient, for administration of oxygen to the patient,while the face-engaging portion is engaged with the patient's face,according to an aspect of the present invention;

FIG. 9 is a sectional view of a second exemplary therapeutic face maskin accordance with an aspect of the present invention;

FIG. 10 is an exploded view the main components of the therapeutic facemask of FIG. 9;

FIG. 11A shows a second exemplary oxygen reservoir bag according to anaspect of the present invention, detachably secured to the therapeuticface mask of FIG. 9;

FIG. 11B shows a second exemplary oxygen reservoir bag according to anaspect of the present invention, detached from the therapeutic face maskof FIG. 9;

FIG. 12A shows a second exemplary nebulizer according to an aspect ofthe present invention, detachably secured to the therapeutic face maskof FIG. 9;

FIG. 12B shows a second exemplary nebulizer according to an aspect ofthe present invention, detached from the therapeutic face mask of FIG.9;

FIG. 13A is cross-sectional view of part of an oxygen reservoir therapybag having an integral metered-dose inhaler port, also showing ametered-dose inhaler, according to an aspect of the present invention;and

FIG. 13B is a cross-sectional showing the oxygen reservoir therapy bagportion shown in FIG. 13A, showing the metered-dose inhaler engaged withthe metered-dose inhaler port.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 2, a therapeutic face mask is indicated generally at210, and has a face-engaging portion 212 and a connector 214. Theface-engaging portion 212 has a peripheral rear edge 216 shaped toengage a patient's face and carrying a pair of attachment straps 217,one of which will encircle the upper portion of a patient's head, abovethe ears, and the other the lower portion of the patient's head, belowthe ears. The face-engaging portion is preferably made from a flexiblePVC material to enable a good fit with a patient's face. As is known inthe art, a bendable nose piece 213, preferably made from aluminum, issecured to the face-engaging portion 212 at the portion thereof whichwill engage the bridge of the patient's nose, to facilitate a betterfit. The face-engaging portion 212 also has a forwardly located,downwardly extending tubular portion 218 defining a fluid aperture 219through which fluid can enter or leave the face-engaging portion 212. Asdescribed below, the connector 214 is received in the tubular portion218.

The connector 214 has a mask-engaging end 222 and a treatment-receivingend 226, and a main tubular body 220 which in use is substantiallyvertical and which defines a fluid passageway between the mask-engagingend 222 and the treatment-receiving end 226. The mask-engaging end 222of the main body portion 220 is a sliding fit in the downwardlyextending tubular portion 218 of the face-engaging portion 212, hence,the mask-engaging end 222 of the connector 214 is coupled to theface-engaging portion 212 in fluid communication with the fluid aperture219. The terminus of the mask-engaging end 222 has an outwardlyprojecting annular shoulder 224 which snaps into engagement with theupper end of the downwardly extending tubular portion 218 to retain themain tubular body 220 of the connector 214 in engagement with thedownwardly extending tubular portion 218. Other suitable attachmenttechniques, such as adhesive or a friction fit, may also be used withoutdeparting from the scope of the present invention.

The treatment-receiving end 226 of the main tubular body 220 has anattachment mounting for detachably sealingly receiving a matingtreatment attachment in fluid communication with the treatment-receivingend 226. In the illustrated embodiment, the attachment mounting isdefined by a tubular terminus 228 at the treatment-receiving end 226which can receive a correspondingly sized tubular neck of a treatmentattachment (shown in FIG. 2 as an oxygen reservoir bag 536, described ingreater detail in respect of FIGS. 5A and 5B) in a friction fit. When atreatment attachment is so received, a fluid passageway is definedbetween the treatment attachment and the fluid aperture 219 by way ofthe main tubular body 220 of the connector 214. Examples of typicaltreatment attachments include oxygen reservoir bags, as shown in FIGS.5A and 5B, and nebulizers, as shown in FIGS. 6A and 6B. Various othertypes of attachment mountings besides the illustrated tubular terminus228 may also be used, without departing from the scope of the presentinvention. All that is required is that the attachment mounting be ableto detachably sealingly receive a mating treatment attachment. Forexample, the attachment mounting may be configured to receive both aconventional nebulizer and an oxygen reservoir bag having acorrespondingly sized neck.

As shown in FIGS. 5A and 5B, the treatment attachment is an oxygenreservoir bag 536. FIG. 5A shows the oxygen reservoir bag 536 detachablyreceived by the tubular terminus 228 at the treatment-receiving end 226of the connector 214, and FIG. 5B shows the oxygen reservoir bag 536detached therefrom. The oxygen reservoir bag 536 includes a neck 530made from rigid material and a flexible oxygen reservoir bag member 535.The oxygen reservoir bag member 535 is sealingly secured to a lower endportion 534 of the neck 530, for example by tape or adhesive, so thatthe interior volume of the oxygen reservoir bag member 535 is in fluidcommunication with the interior volume of the neck 530. The neck 530includes an open upper end portion 533 having an outer diametercorresponding to the inner diameter of the tubular terminus 228 at thetreatment-receiving end 226 of the connector 214. Thus, the neck 530 isshaped, by way of the upper end portion 533, for removable coupling ofthe oxygen reservoir bag 536 to a mating connector of a therapeutic facemask, namely the connector 214, the treatment-receiving end 226 of whichreceives the upper end portion 533 in sliding frictional engagementtherewith. The neck 530 also has a laterally extending tube attachmentmember 538 in fluid communication with the neck 530, to which one end541 of an oxygen supply tube 540 can be detachably connected, the otherend of the oxygen supply tube 541 being connected to a source ofpressurized oxygen in known manner. It is to be noted that the neck 530does not carry any valves to govern fluid flow through the neck 530,that is, the neck 530 is valveless. As will be explained below, no valveneed be included in the neck 530 because the oxygen reservoir bag 530 isto be used in conjunction with a therapeutic face mask having aconnector that includes the requisite valve arrangements.

As shown in FIGS. 6A and 6B, the treatment attachment is a nebulizer.FIG. 6A shows the nebulizer 680 detachably received on the tubularterminus 228 at the treatment-receiving end 226 of the connector 214,and FIG. 6B shows the nebulizer 680 detached therefrom. The nebulizer680 shown in FIGS. 6A and 6B comprises a medication cup 682 in which aquantity of liquid medication may be disposed, and a removable cap 684.A tube attachment member 686 (FIG. 6B) is adapted to detachably receiveone end 641 of an oxygen (or oxygen/air mixture) supply tube 640, anddefines a fluid communication path from the supply tube 640 into themedication cup 682. The cap 684 includes an upwardly extending neck 688(FIG. 6B) which is shaped to enable removable coupling of the nebulizer680 to a mating connector of a therapeutic face mask, namely theconnector 214. In particular, the outer diameter of the upwardlyextending neck 688 corresponds to the inner diameter of the tubularterminus 228 at the treatment-receiving end 226 of the connector 214, sothat the treatment-receiving end 226 of the connector 214 can receivethe upwardly extending neck 688 in a friction fit. Particular details ofthe operation of the nebulizing or atomizing structure of the nebulizer680 are outside the scope of the present invention.

As will be explained in greater detail below, because the attachmentmounting at the treatment-receiving end 226 of the connector 214 candetachably sealingly receive a treatment attachment, a health careworker can change the treatment attachment without having to remove thetherapeutic face mask 210 from the user's face, which, by way of thevalve structure and filter attachment to be described shortly, allowsthe patient to remain isolated during the changeover of treatmentattachment.

Now referring primarily to FIG. 3, and also to FIG. 2, the connector 214has an inhalation valve 250 interposed in the main tubular body 220between the mask-engaging end 222 and the treatment-receiving end 226.The inhalation valve 250 is a one-way valve and is oriented to permitfluid flow from the treatment-receiving end 226 through themask-engaging end 222 and to inhibit fluid flow from the mask-engagingend 222 through the treatment-receiving end 226. Thus, when thetreatment attachment that is attached to the tubular terminus 228 at thetreatment-receiving end 226 of the connector 214 is an oxygen reservoirbag, such as the exemplary oxygen reservoir bag 536, oxygen (or anoxygen/air mixture) from the oxygen reservoir bag 536 and the oxygensupply tube 540 can pass through the main tubular body 220 of theconnector 214 to the interior of the face-engaging portion 212.Similarly, and as will be explained in greater detail below, when thetreatment attachment is a nebulizer, the oxygen (or oxygen/air mixture)containing the atomized medication can also pass through the maintubular body 220 of the connector 214 to the interior of theface-engaging portion 212. In the illustrated embodiment, only a singleinhalation valve 250 is shown, it is contemplated that in otherembodiments an assembly comprising more than one one-way inhalationvalve could be used.

As best seen in FIG. 2A, in the exemplary connector 214, the inhalationvalve 250 comprises a flexible circular diaphragm 252 secured by aretainer 254 at its centre to two substantially mutually perpendicularcross members 256, 258 extending across the main tubular body 220 of theconnector. The diaphragm 252 is located on the side of the cross members256, 258 closest to the mask-engaging end 222 of the connector 214 sothat, when the patient inhales, the diaphragm 252 bends upwardly asshown in FIGS. 2 and 3 to permit fluid to flow therethrough from theoxygen reservoir bag 536 and/or supply tube 540, or from the nebulizer680, into the face-engaging portion 212 and thence to the patient. Whenthe patient is not inhaling, the diaphragm 252 rests against the crossmembers 256, 258 to inhibit airflow from the face-engaging portion 212into the treatment-receiving end 226. More particularly, when a patientexhales, the diaphragm 252 is supported by the cross members 256, 258,which helps to prevent bending of the diaphragm 252 under pressure fromthe exhaled air. Preferably, an annular shoulder 259 is defined adjacentthe diaphragm 252 on the side thereof closest to the treatment-receivingend 226 of the connector 14, and the diaphragm 252 is sized so that itscircumferential edge rests on and is supported by the annular shoulder259 when the patient exhales, to provide a more effective seal.

The presence of the inhalation valve 250 helps to facilitate effectivedelivery of medication with a nebulizer, such as the nebulizer 680. Manyof the known types of nebulized medication procedures are continuous, inthat the flow of oxygen or oxygen/air mixture, and hence of the atomizedmedication, into the face-engaging portion is continuous. When aconventional nebulizer mask, such as the nebulizer mask 110C illustratedin FIG. 1C, is used, this results in waste of medication duringexhalation or coughing, as the medication-laden oxygen or oxygen/airmixture is expelled through the exhalation apertures. This also resultsin unwanted exposure of the health care worker to medication.

These problems are substantially obviated with the use of a therapeuticface mask according to an aspect of the present invention. When theoxygen reservoir bag 536 is removed and replaced with the nebulizer 680,the inhalation valve 250 acts as a lid because of its measured thicknessand relative rigidity. While a patient is exhaling, the inhalation valve250 is in the closed position, and atomized medication particlescontained in the continuous flow of oxygen (or oxygen air/mixture)entering the nebulizer are deflected by the inhalation valve 250 to“rain” back into the nebulizer, rather than entering the face-engagingportion 212, thereby substantially reducing aerosol release to theambient air during exhalation. The inhalation valve 250 only opens oninhalation to allow the atomized medication particles to enter theface-engaging portion 212 to be supplied to the patient. Thus, theprocess of medication delivery with a therapeutic face mask inaccordance with the present invention is more efficient andsignificantly reduces undesirable exposure of a care giver tomedication.

A therapeutic face mask according to an aspect of the present inventionincludes at least one exhalation port in fluid communication with theface-engaging portion. The exhalation port should be positioned todefine an exhalation path from the face-engaging portion to ambientwhich bypasses the inhalation valve, so that the inhalation valve (whichis a one-way valve) does not obstruct exhalation. In one preferredembodiment, as will be described in greater detail below, ananti-asphyxia valve assembly is associated with the exhalation port. Inthe illustrated embodiment 210 there is a single exhalation port andassociated anti-asphyxia valve assembly, it is contemplated that inother embodiments multiple exhalation ports and associated valveassemblies could be provided.

As best seen in FIG. 3, in the exemplary therapeutic face mask 10, anexhalation port 265 includes an exhalation aperture 261 defined in aside wall of the connector 214, that is, in the main tubular body 220 ofthe connector 214, and is in fluid communication with the face-engagingportion 212 by way of the fluid passageway defined by the main tubularbody 220. Thus, the exhalation port 265 enables communication betweenthe interior of the face-engaging portion 212 and the ambientatmosphere. As can be seen, the exhalation port 265 is positionedbetween the inhalation valve 250 and the mask-engaging end 222 of theconnector 214, and there is thus be defined an exhalation path betweenthe face-engaging portion 212 and ambient which bypasses the inhalationvalve 250.

The exhalation port 265 also includes a laterally extending tubularoutlet portion 260 which surrounds the exhalation aperture 261, andwhich defines a filter mounting for detachably sealingly receiving afilter assembly. A filter assembly 270 may be detachably connected tothe outlet portion 260. More particularly, the filter assembly 270 (bestseen in FIG. 2) comprises a tubular body having one tubular end portion272 slidable over the tubular outlet portion 260 in a friction fittherewith and an outer end portion 274 in communication with the ambientatmosphere. The filter assembly 270 contains a filter 276 to filter airpassing into the ambient atmosphere from the exhalation port 265 to theinterior of the face-engaging portion 212 and vice-versa (as explainedbelow). FIG. 2C shows the filter assembly 270 detached from thetherapeutic face mask 210.

In the exemplary oxygen therapy mask 210, the anti-asphyxia valveassembly is associated with the exhalation port 265 and comprises asingle two-way valve 262 disposed in the exhalation port and oriented topermit fluid flow from the connector 214 to ambient through theexhalation port 265, to inhibit fluid flow from ambient to the connector214 through the exhalation port 265 during inhalation when sufficientfluid is supplied to the treatment-receiving end 226 of the connector,and to permit fluid flow from ambient to the connector 214 through theexhalation port 265 during inhalation when fluid flow to thetreatment-receiving end 226 of the connector 214 is less than theinspiratory effort of the patient during inhalation. Thus, the two-wayvalve 262 governs the exhalation port 265.

The single two-way anti-asphyxia valve 262 is disposed in the tubularoutlet portion 260, at the junction between the tubular outlet portion260 and the main body 220 of the connector 214. As best seen in FIG. 2B,the two-way valve 262 comprises a single cross member 264 extendingacross the exhalation aperture 261 between opposed sides of the tubularoutlet portion 260. A flexible circular diaphragm 266 is secured to thecentre of the cross member 264 by a retainer 268, the diaphragm 266being on the outer side of the cross member 264 relative to the fluidpassageway defined by the connector 214. The outer diameter of thediaphragm 266 is preferably equal, with appropriate tolerance, to theinner diameter of the tubular outlet portion 260, so that thecircumferential edge of the diaphragm 266 engages the inner surface ofthe tubular outlet portion 260 to assist in sealing.

Depending on whether oxygen (or an oxygen/air mixture, or an oxygen oroxygen/air mixture containing nebulized medication) is supplied to thetreatment-receiving end 226 of the connector 214, inhaling by thepatient may cause the two-way valve 262 to open to permit air from theambient atmosphere to flow therethrough to the interior of theface-engaging portion 212, with the diaphragm 266 bending around thecross member 264. In particular, as long as sufficient oxygen (oroxygen/air mixture, or oxygen or oxygen/air mixture containing nebulizedmedication) is supplied to the treatment-receiving end 226 of theconnector 214, when the patient inhales the inhalation valve 250 will beopen, and the inflow of oxygen (or oxygen/air mixture) through theinhalation valve 250 will maintain sufficient pressure in the connector214 that the diaphragm 266 will not be drawn inward and willsubstantially seal the exhalation aperture 261, thus inhibiting fluidflow from ambient to the connector 214 through the exhalation port 265during inhalation. However, if oxygen (or an oxygen/air mixture, or anoxygen or oxygen/air mixture containing nebulized medication) suppliedto the treatment-receiving end 226 of the connector 214 is absent orinsufficient, such as if the oxygen supply tank is empty, or the oxygensupply tube is obstructed, then inhalation by the patient will generatenegative pressure inside the connector 214, which draws the diaphragm266 inward and causes it to bend around the cross member 264, so thatair can flow from ambient through the exhalation aperture 261 into theconnector 214 and then into the face-engaging portion 212 so that thepatient does not suffocate. Thus, the two-way valve 262 governs theexhalation port 265, and permits fluid flow from the face-engagingportion to ambient (i.e. during exhalation) and inhibits fluid flow fromambient to the face-engaging portion 212 up to the point at which fluidflow to the treatment-receiving end 226 of the connector 214 exceeds thepatient's inspiratory effort during inhalation, after which the two-wayvalve 262 permits fluid flow from ambient to supplement or replace fluidflow to the treatment-receiving end 226 of the connector 214. Thus, thetwo-way valve 262 is configured to permit fluid flow therethrough fromambient to the face-engaging portion 212 during inhalation only whenfluid flow to the treatment-receiving end 226 of the connector 212 isless than inspiratory effort during inhalation. The relative rigidity ofthe diaphragm 252 of the inhalation valve, and of the diaphragm 266 ofthe two-way valve 262, should be selected to achieve the aforementionedeffect. In a preferred embodiment, the inhalation valve 250 will open atan inspiratory effort of approximately 0.5 cm H₂O/l/second, and thetwo-way valve 262 opens to permit fluid flow from the face-engagingportion 212 to ambient (i.e. exhalation) at approximately 0.75 cmH₂O/l/second, and opens to permit fluid flow therethrough from ambientto the face-engaging portion at an inspiratory effort of approximately1.5 cm H₂O/l/second.

When the patient exhales, the inhalation valve 250 remains closed andthe two-way valve 262 opens by movement of the diaphragm 266 away fromthe cross member 264 under pressure from the exhaled air, allowing theexhaled air to escape to ambient.

As noted above, because the attachment mounting can detachably sealinglyreceive a treatment attachment, the treatment attachment may be changedwithout removing the therapeutic face mask 210 from the user's face,which, by way of the above-described inhalation valve 250, anti-asphyxiavalve 262 and filter assembly 270, allows the patient to remain isolatedwhile the treatment attachment is changed. For example, when medicationis to be administered to a patient who had previously been receivingoxygen or an oxygen/air mixture, the oxygen reservoir bag 536 which wasattached to the tubular terminus 228 of the connector 214 (FIG. 5A) isremoved from the tubular terminus 228 of the connector 214 (FIG. 5B) andis replaced by a medication supplying nebulizer 680, as shown in FIG.6A. Similarly, when oxygen or an oxygen/air mixture is to be supplied toa patient who had been receiving medication, the medication supplyingnebulizer 680 which was attached to the tubular terminus 228 of theconnector 214 (FIG. 6A) is removed from the tubular terminus 228 of theconnector 214 (FIG. 6B) and is replaced by a oxygen reservoir bag 536,as shown in FIG. 5A.

Thus, according to an aspect of the present invention, an oxygen therapyface mask has a face-engaging portion with an inlet passage throughwhich oxygen from a pressurized source can be received. A valve assemblyconnected to the inlet passage has a first one-way valve operable topermit flow of oxygen from a source thereof to the patient and preventflow in the opposite direction, the valve assembly also having aninlet/outlet passage with a two-way valve permitting ambient air to flowto the patient and permitting exhaled air to flow from the patient tothe ambient atmosphere.

The valve assembly may have a first tubular inlet portion to which anoxygen reservoir bag may be detachably connected, the first tubularinlet portion also being capable of detachably receiving, in the absenceof the oxygen reservoir bag, a medication supplying nebulizer, wherebymedication can be supplied by the nebulizer through the one-way valveinto the face-engaging portion for passage to the patient.

The inlet/outlet passage may have a tubular portion connecting thetwo-way valve with the ambient atmosphere, the tubular portion beingcapable of detachably receiving a filter assembly operable to filter airpassing from the ambient atmosphere to the two-way valve and from thetwo-way valve to the ambient atmosphere.

The two-way valve may comprise a rod-like support member extendingacross the inlet/outlet passage and a diaphragm mounted on the supportmember and having a closed position blocking air flow through theinlet/outlet valve, the diaphragm being bendable by air pressure fromeither side thereof to enable air to flow through the valve from thehigher pressure side of the diaphragm to the lower pressure sidethereof.

Referring now to FIG. 7, an exemplary method of preparing a therapeuticface mask, that is configured for oxygen administration, foradministration of inhaled medication to a patient, while theface-engaging portion of the therapeutic face mask is engaged with thepatient's face, is shown generally at 700. At step 702, an oxygenreservoir bag that is detachably secured to the therapeutic face mask influid communication with a face-engaging portion of the therapeutic facemask is removed from the therapeutic face mask, while the face-engagingportion remains engaged with the patient's face and a filter associatedwith the therapeutic face mask face filters air exhaled by the patient.At step 704, a nebulizer is detachably secured to the therapeutic facemask in place of the oxygen reservoir bag so that the nebulizer is influid communication with the face-engaging portion of the therapeuticface mask while the face-engaging portion remains engaged with thepatient's face and a filter associated with the therapeutic face maskface filters air exhaled by the patient. The steps of the method 700would typically, but not necessarily, be carried out by a health careworker. The method 700 may be carried out, for example, with atherapeutic face mask such as the therapeutic face mask 210, with theoxygen reservoir bag being removed from the treatment-receiving end 226of the connector 220, and the nebulizer being detachably secured to thetreatment-receiving end 226 of the connector 220. As such, the filteremployed in the method would be the filter included in the filterassembly 270.

In a similar manner, when oxygen or an oxygen/air mixture is to beadministered to a patient who had previously been receiving medicationvia a nebulizer, the nebulizer attached to the therapeutic face mask(FIG. 6A) is removed from the tubular terminus 228 of the connector 214(FIG. 6B) and is replaced by the oxygen reservoir bag 536, as shown inFIG. 5A.

With reference now to FIG. 8, an exemplary method 800 of preparing atherapeutic face mask, configured for administration of inhaledmedication to a patient, for oxygen administration, while theface-engaging portion is engaged with the patient's face, is shown. Atstep 802, a nebulizer that is detachably secured to the therapeutic facemask in fluid communication with a face-engaging portion of thetherapeutic face mask is removed from the therapeutic face mask, whilethe face-engaging portion remains engaged with the patient's face and afilter associated with the therapeutic face mask face filters airexhaled by the patient. At step 804, an oxygen reservoir bag isdetachably secured to the therapeutic face mask in place of thenebulizer so that the oxygen reservoir bag is in fluid communicationwith the face-engaging portion of the therapeutic face mask while theface-engaging portion remains engaged with the patient's face and afilter associated with the therapeutic face mask face filters airexhaled by the patient. As with the method 700, the steps of the method800 may be carried out by a health care worker, and the method 800 maybe carried out, for example, with a therapeutic face mask such as thetherapeutic face mask 210, with the nebulizer 680 being removed from thetreatment-receiving end 226 of the connector 214, and the oxygenreservoir bag 536 being detachably secured to the treatment-receivingend 226 of the connector 214.

Other types of masks may be modified in accordance with aspects of thepresent invention to enable selective removable attachment of atreatment attachment, such as a nebulizer and an oxygen reservoir bag.For example, a therapeutic face mask having certain structural featuressimilar to those of the oxygen therapy face mask disclosed in U.S. Pat.No. 7,360,538 may be modified and adapted in accordance with aspects ofthe present invention. U.S. Pat. No. 7,360,538 is hereby incorporated byreference in its entirety.

Referring now to FIGS. 9 and 10, a therapeutic face mask having certainstructural features similar to those described and depicted in U.S. Pat.No. 7,360,538, and adapted in accordance with aspects of the presentinvention, is now described. This therapeutic face mask is denotedgenerally by the reference numeral 910. The therapeutic face mask 910has a face-engaging portion 912 and a connector 914 connected thereto,with the connector 914 including a valve assembly 915. As with thetherapeutic face mask 210, the face-engaging portion 912 has aperipheral rear edge 909 shaped to engage a patient's face and carryinga pair of attachment straps 911, one of which will encircle the upperportion of a patient's head, above the ears, and the other the lowerportion of the patient's head, below the ears, and a bendable nose piece913.

The connector 914 comprises an upper tubular body portion 916 and alower tubular body portion 918 connected to each other. The uppertubular body portion 916 has its upper end portion 917, that is, itsmask-engaging end 917, inserted into a downwardly extending tubularportion 920 which defines a fluid aperture of the face-engaging portion912, thus, the mask-engaging end 917 of the connector 914 is coupled tothe face-engaging portion 912 in fluid communication with the fluidaperture thereof. The upper tubular body portion 916 may be securedwithin the downwardly extending tubular portion 920 of the face-engagingportion 912 by way of a friction fit, adhesive, or may be modified toinclude an outwardly projecting annular shoulder (not shown), similar tothe outwardly projecting annular shoulder 224 of the therapeutic facemask 10, which snaps into engagement with a corresponding annularshoulder (not shown) at the upper end of the downwardly extendingtubular portion 920.

The upper tubular body portion 916 provides a first passage 922 adjacentthe mask-engaging end 917 of the connector 914, from which first passage922 fluid can flow into the face-engaging portion 912 and which can alsoreceive fluid from the interior of the face-engaging portion 912. Thelower end portion 924 of the upper tubular body portion 916 is enlarged,as also is the upper end portion 926 of the lower tubular body portion918. The enlarged upper end portion 926 of the lower tubular bodyportion 918 is secured to the enlarged lower end portion 924 of theupper tubular body portion 916. The lower tubular body portion 918provides a second passage 928 adjacent the treatment-receiving end 919of the connector 914. The treatment-receiving end 919 of the connector914 has an attachment mounting for detachably sealingly receiving atreatment attachment in fluid communication therewith. In theillustrated embodiment, the attachment mounting is defined by thetubular shape of the treatment-receiving end 919 of the connector 914,which can receive a correspondingly sized tubular neck of a treatmentattachment in a friction fit to define a fluid passageway, by way of theconnector 914, between the treatment attachment and the downwardlyextending tubular portion 920 defining the fluid aperture of theface-engaging portion 912.

The connector 914 includes a valve assembly 915 which is disposedwithin, and includes portions of, the enlarged upper end portion 926 ofthe lower tubular body portion 918 and the enlarged lower end portion924 of the upper tubular body portion 916.

The valve assembly 915 includes an inhalation valve 930, which is aone-way valve 930, and is associated with the first passage 922 and thesecond passage 928. Specifically, the inhalation valve 930 is providedat the junction of the first and second passages 922, 928 and istherefore interposed in the fluid passageway defined by the connector914 between the mask-engaging end 917 and the treatment-receiving end919 thereof. The inhalation valve 930 is operable to permit fluid flowfrom the second passage 928 to the first passage 922 during inhalationand inhibit fluid flow from the first passage 922 to the second passage928, and thus is oriented to permit fluid flow from thetreatment-receiving end 919 through the mask-engaging end 917 and toinhibit fluid flow from the mask-engaging end 917 through thetreatment-receiving end 919. In the illustrated embodiment, theinhalation valve 930 comprises a disk-like diaphragm 932 at the upperend of the second passage 928. The disk-like diaphragm 932 is retainedin position by a central headed pin 933 carried by the lower tubularbody portion 918, and is movable between open and closed positions.Normally, the diaphragm 932 is in the closed position and closes theupper end of the second passage 928 and remains closed when the patientexhales, but a sufficiently lower pressure in the first passage 922relative to the pressure in the second passage 928, such as would becaused by a patient inhaling, causes the diaphragm 932 to move upwardlyinto the open position and permit fluid to flow from the second passage928 into the first passage 922 and hence into the face-engaging portion912. Preferably, the inhalation valve 930 will open when the patientexerts an inspiratory effort of approximately 1.0 cm H₂O/l/second. Inthe illustrated embodiment, only a single inhalation valve 930 is shown,it is contemplated that in other embodiments an assembly comprising morethan one one-way inhalation valve could be used.

The valve assembly 915 also includes an exhalation port 921 defined inthe connector 914 and which is in fluid communication with theface-engaging portion 912 by way of the fluid passageway defined by theconnector 914. The exhalation port 921 includes a one-way exhalationvalve 940, which is operable to permit fluid flow from the first passage922 to the external atmosphere and to inhibit fluid flow from theexternal atmosphere to the first passage 922. As can be seen, theexhalation port 921 is positioned to define an exhalation path betweenthe face-engaging portion 912 and ambient which bypasses the inhalationvalve 930. The exhalation valve 940 comprises an annular diaphragm 942which surrounds the disk-like diaphragm 932 of the inhalation valve 930and is retained by an annular lip 943 on the lower end of the upper endportion 926 of the lower tubular body portion 918. The exhalation port921 also includes one or more exhalation apertures 944 defined in thelower part of the enlarged upper portion 926 of the lower tubular bodyportion 918. Thus, the exhalation valve 940 is associated with the firstpassage 922. The exhalation apertures 944 are normally closed by theannular diaphragm 942, and the exhalation valve 940 preferably opens(i.e. the annular diaphragm 942 bends away from the exhalation apertures944 to permit fluid flow therethrough) at approximately 1.2 cmH₂O/l/second and the patient can exhale normally. Accordingly, theexhalation valve 940 governs the exhalation port 921, and which permitsfluid flow from the face-engaging portion to ambient during exhalation.The exhalation valve 940 also inhibits fluid flow from ambient to theface-engaging portion 912 not only when fluid flow to thetreatment-receiving end 919 of the connector 914 exceeds inspiratoryeffort during inhalation, but also when such fluid flow is equal to orless than inspiratory effort during inhalation. When fluid flow to thetreatment-receiving end 919 of the connector 914 is less thaninspiratory effort during inhalation, the anti-asphyxia valve assemblydescribed below will assist in preventing asphyxiation. In theillustrated embodiment, a single exhalation valve 940 is provided, inother embodiments, multiple exhalation valves may be used.

Optionally, an annular filter 948 having a central aperture 970 isdisposed in the valve assembly 915 to filter air exhaled by a patient.Specifically, the annular filter 948 is positioned in the valve assembly915 to filter fluid flow from the first passage 922 through theexhalation port 921 to ambient, and to permit unfiltered fluid flow fromthe second passage 928 to the first passage 922 through its centralaperture 970.

In the illustrated embodiment, the annular filter 948 is carried by anannular filter support 960 comprising radially spaced inner and outercylindrical walls 962, 964, respectively. The inner cylindrical wall 962is connected to the outer cylindrical wall 964 by a plurality ofradially extending spokes 966 which define a plurality of apertures 968(see FIG. 10) therebetween, and which also support the annular filter948. The edges of the inner and outer cylindrical walls 962, 964opposite the spokes 966 are secured in fluid-tight, sealing engagementwith the base of the enlarged upper end portion 926 of the lower tubularbody portion 918, with the annular filter support 960 and hence theannular filter member 948 generally surrounding the inhalation valve930, so that the central aperture 970 defined by the annular filtersupport 960 and the annular filter 948 is generally aligned with theinhalation valve 930. Accordingly, fluid entering the connector 914 viathe second passage 928 and passing through the inhalation valve 930 isable to pass through the central aperture 970 to the first passage 922without being filtered. Thus, when the treatment attachment is anebulizer, the atomized medication will not be filtered out of the fluidbefore reaching the patient. When a patient exhales, the exhaled air isinhibited from travelling from the first passage 922 to the secondpassage 928 by the one-way inhalation valve 930, and the innercylindrical wall 962 prevents the exhaled air from reaching theexhalation valve 940 without passing through the annular filter 948. Inan alternate embodiment (not shown), an annular filter may surround theinhalation valve 930 at the base of the enlarged upper end portion 926to cover the exhalation apertures 944, so that exhaled air passingthrough the exhalation apertures 944 must also pass through the annularfilter while incoming oxygen (or an oxygen/air mixture, or amedication-laden oxygen/air mixture) passes through the central apertureof the annular filter and therefore is not filtered.

The valve assembly 915 further comprises an anti-asphyxia valve assemblywhich includes a one-way anti-asphyxia valve 950. As will be explainedin greater detail below, the anti-asphyxia valve 950 is operable topermit fluid flow from the external atmosphere to the first passage 922when fluid flow into the second passage 928 is less than inspiratoryeffort of the patient during inhalation, and to inhibit fluid flow fromthe first passage 922 to the external atmosphere. The anti-asphyxiavalve 950 comprises an annular diaphragm 952 retained at the top of theenlarged lower end portion 926 of the upper tubular body portion 916 byan annular lip 953. Thus, the anti-asphyxia valve 950 is associated withthe first passage 922. The annular diaphragm 952 normally closes one ormore anti-asphyxia apertures 954 in the enlarged lower end portion 924of the upper tubular body portion 916 to isolate the first passageway922 from the external atmosphere. The construction of the inhalationvalve 930 and the anti-asphyxia valve 950 is such that the anti-asphyxiavalve 950 normally remains closed when oxygen (or an oxygen/air mixtureor medication-laden oxygen air mixture) is being inhaled by a patientafter passage through the inhalation valve 930. In a preferredembodiment, this is achieved by a valve construction in which theinhalation valve 930 opens when the patient exerts an inspiratory effortof a approximately 1.0 cm H₂O/l/second (as noted above) and theanti-asphyxia valve 950 opens (i.e. the annular diaphragm 952 bends awayfrom the anti-asphyxia apertures 954 to permit fluid flow therethrough)at an inspiratory effort of approximately 1.3 cm H₂O/l/second. Thus, theanti-asphyxia valve 950 opens to permit fluid flow therethrough fromambient to the face-engaging portion 912 during inhalation only whenfluid flow to the treatment-receiving end 919 of the connector 914 isless than inspiratory effort during inhalation. In the illustratedembodiment, a single anti-asphyxia valve 950 is provided, in otherembodiments, multiple anti-asphyxia valves may be used.

As indicated above, the tubular shape of the treatment-receiving end 919of the connector 914 defines an attachment mounting which can receive acorrespondingly sized tubular neck of a treatment attachment in afriction fit. Examples of suitable attachment mountings include oxygenreservoir bags, and nebulizers.

As shown in FIGS. 11A and 11B, the treatment attachment is an oxygenreservoir bag 1136. FIG. 11A shows an oxygen reservoir bag 1136detachably mounted on the treatment-receiving end 919 of the connector914, and FIG. 11B shows oxygen reservoir bag 1136 detached therefrom.The oxygen reservoir bag 1136 includes a neck 1130 made from rigidmaterial and a flexible oxygen reservoir bag member 1135. The oxygenreservoir bag member 1135 is sealingly secured to a lower end portion1134 of the neck 1130, and the neck 1130 includes an open upper endportion 1133 whose outer diameter corresponds to the inner diameter ofthe lower tubular body portion 918 at the treatment-receiving end 919 ofthe connector 914. Thus, the neck 1130 is shaped, by way of the upperend portion 1133, to enable the oxygen reservoir bag 1136 to beremovably secured to a mating connector of a therapeutic face mask, inthis case the lower tubular body portion 918 defining thetreatment-receiving end 919 of the connector 914, which can receive theupper end portion 1133 in a friction fit. A tube attachment member 1138extends laterally from the neck 1130 in fluid communication therewith,for detachably receiving one end 1141 of an oxygen supply tube 1140. Aswith the oxygen reservoir bag 536, the neck 1130 is valveless; there isno need to include a valve in the neck 1130 because of the valveassembly 915 included in the therapeutic face mask 910.

As shown in FIGS. 12A and 12B, the treatment attachment is a nebulizer.FIG. 12A shows a nebulizer 1280 detachably mounted on thetreatment-receiving end 919 of the connector 914, and FIG. 11B shows thenebulizer 1280 detached therefrom. Like the nebulizer 680, the nebulizer1280 shown in FIGS. 12A and 12B comprises a medication cup 1282 forcontaining liquid medication, and a removable cap 1284. A tubeattachment member (not shown) for detachably receiving one end 1241 ofan oxygen (or oxygen/air mixture) supply tube 1240 extends downwardly todefine a fluid communication path from the supply tube into themedication cup 1282. The cap 1284 has an upwardly extending neck 1288which is shaped for removable attachment of the nebulizer 1280 to amating connector of a therapeutic face mask, in this case the lowertubular body portion 918 defining the treatment-receiving end 919 of theconnector 914. In particular, the upwardly extending neck 1288 has anouter diameter corresponding to the inner diameter of the lower tubularbody portion 918 defining the treatment-receiving end 919 of theconnector 914, enabling a friction fit of the upwardly extending neck1288 within the treatment-receiving end 919 of the connector 914. Aswith the nebulizer 680, the particular details of the operation ofnebulizing or atomizing structure of the nebulizer 1280 are outside thescope of the present invention.

Referring again to FIG. 9, when the face-engaging portion 912 has beenplaced over the patient's mouth and nose, with either an oxygenreservoir bag 1136 (FIGS. 11A and 11B) or a nebulizer 1280 (FIGS. 12Aand 12B) in place and connected to a supply of oxygen or oxygen/airmixture, inhaling by the patient will cause the inhalation valve 930 toopen so that oxygen (or an oxygen/air mixture, or a medication-ladenoxygen/air mixture) passes through the second passage 928, through theinhalation valve 930 and through the central aperture in the annularfilter 948, to the first passage 922 and into the face-engaging portion912 and thence into the patient's mouth and nose. The pressure of theoxygen in the second passage 928 assists with the opening of theinhalation valve 930 when the patient inhales (with consequent loweringof pressure in the first passage 922). The lower pressure in the firstpassage 922 causes the exhalation valve 940 to remain closed. Theanti-asphyxia valve 950 also remains closed because the lower pressurein the first passage 922 is not sufficiently low to cause it to open.

When the patient exhales, the increase in pressure in the first passage922 causes the inhalation valve 930 to close and the anti-asphyxia valve950 to remain closed. The increase in pressure in the first passage 922then causes the exhalation valve 940 to open so that air in the firstpassage 922 passes therethrough (after passing through the annularfilter 948) to the external atmosphere. The filter 948 filters the airexhaled by the patient, thereby filtering not only airborne pathogens,but also filtering excess medication when a nebulizer is attached to thetreatment-receiving end 919.

Such inhaling and exhaling continues while the oxygen (or oxygen/airmixture) supply to the second passage 928 is sufficient, with the oxygenreservoir bag 1136 or the nebulizer 1280 functioning in the conventionalmanner. If the oxygen (or oxygen/air mixture) supply ceases, so thatthere is little or no oxygen flow through the inhalation valve 930,further lowering of pressure in the first passage 922 produced by thepatient inhaling more strongly causes the anti-asphyxia valve 950 toopen. Air is then drawn through the anti-asphyxia valve 950 from theexternal atmosphere into the first passage 922 and hence to the patient.

Accordingly, so long as oxygen (or an oxygen/air mixture ormedication-laden oxygen/air mixture) is supplied to the treatmentreceiving end 919 of the connector 914, the patient will inhale thesupplied gas through the inhalation valve 930, and exhale through theexhalation valve 940. In addition, if a patient's peak inspiratoryeffort exceeds the flow rate of the supplied gas, the anti-asphyxiavalve 950 will open to provide supplementary air to match theinspiratory effort. Moreover, if the gas supply to the treatmentreceiving end 919 of the connector 914 should cease, such as where anoxygen tank is empty, the patient can inhale normally through theanti-asphyxia valve 950 to avoid asphyxiation, and continue to exhalethrough the exhalation valve 940.

Thus, neither the patient nor medical personnel need to tamper with theface mask if the oxygen supply fails. Optionally, the anti-asphyxiavalve 950 can be configured to include a second annular filter (notshown) to filter incoming atmospheric air.

It is to be appreciated that the relative placement of the exhalationvalve 940 and the anti-asphyxia valve 950 may be reversed, with suitableminor modifications to the structure of the connector 914, withoutdeparting from the scope of the present invention.

Either of the methods 700, 800 may be performed using a therapeutic facemask such as the therapeutic face mask 910 described above.

With reference now to FIGS. 13A and 13B, according to another aspect ofthe present invention an oxygen therapy reservoir bag may be providedwith a metered-dose inhaler port. Metered-dose inhalers are well known,and an exemplary metered-dose inhaler is indicated generally at 1310.The metered-dose inhaler 1310 comprises a container 1312, a meteredvalve (not shown) and an actuator tube 1314. The medication, along witha propellant, is stored in the container. As is known, when the actuatortube 1314 is moved toward the container 1312, it actuates the meteredvalve, thereby enabling a measured dose of aerosolized medicine toescape the container through the metered valve, and pass through theactuator tube 1314. Typical types of medication for which metered-doseinhalers are used include bronchodilators and corticosteroids.

FIG. 13 also shows an exemplary oxygen reservoir bag 1336 according toan aspect of the present invention, which also includes a metered-doseinhaler port 1350. The exemplary oxygen reservoir bag 1336 comprises arigid neck 1330 and a flexible oxygen reservoir bag member 1335 which issealingly secured to a lower end portion 1334 of the neck 1330 so thatthe interior volume 1337 of the oxygen reservoir bag member 1335 is influid communication with the interior volume 1339 of the neck 1330. Theneck 1330 includes an open upper end portion 1333 having an outerdiameter corresponding to the inner diameter of the treatment-receivingend to which it is to be coupled. For example, the exemplary oxygenreservoir bag 1336 could be coupled to either of the therapeutic facemasks 210, 910, or to other therapeutic face masks constructed accordingto aspects of the of the present invention, or to conventional oxygentherapy face masks. Thus, the neck 1330 is shaped, by way of the upperend portion 1333, for removable coupling of the oxygen reservoir bag1336 to a mating connector of a therapeutic face mask. A laterallyextending tube attachment member 1338 for receiving an oxygen supplytube (not shown) extends outwardly from the neck 1330 and is in fluidcommunication with the interior volume 1339 of the neck 1330. A diffuserplate 1340 is opposed to and spaced from the tube attachment member 1338to assist in directing the incoming oxygen (or oxygen/air mixture) fromthe tube attachment member 1338 into the interior volume 1337 of theoxygen reservoir bag member 1335. In the illustrated embodiment, theneck 1330 is valveless in that it does not have any valves disposedtherein to govern fluid flow therethrough because the oxygen reservoirbag 1330 is to be used in conjunction with a therapeutic face maskhaving a connector that includes the requisite valve arrangements; it isalso contemplated that a metered-dose inhaler port according to anaspect of the present invention may be provided in the neck of an oxygenreservoir bag 1330 that is permanently secured to a face-engagingportion of a therapeutic face mask and may hence include a valve.

Referring now specifically to FIG. 13A, the metered dose inhaler port1350 is defined in the neck 1330 at a region 1352 of increasedthickness. The metered dose inhaler port 1340 comprises an inner channel1354 and an outer channel 1356, each of which is defined in the neck1330. The inner channel 1354 is the neck in fluid communication with theinterior volume 1339 of the neck of the neck 1330, and the outer channel1356 is in fluid communication with the ambient environment. Inaddition, the inner and outer channels 1354, 1356 are in fluidcommunication with one another. As can be seen, the outer channel 1356is larger than the inner channel 1354 so as to define a shoulder 1360therebetween. The outer channel 1356 is sized to receive the actuatortube 1314 of the metered-dose inhaler 1310. In the illustratedembodiment, the inner channel 1354 and the outer channel 1356 arecylindrical and are coaxial with one another, so that the shoulder 1360is an annular shoulder. However, other channel shapes may be used, andthe channels 1354, 1356 may be of dissimilar shapes, and need not becoaxial. The inner channel 1354 is angled toward the oxygen reservoirbag member 1335.

Referring now to FIG. 13B, when a medication contained in a metered-doseinhaler is to be administered to a patient wearing a therapeutic facemask including an oxygen reservoir bag such as the oxygen reservoir bag1336, the actuator tube 1314 of the metered-dose inhaler 1310 isinserted into the metered-dose inhaler port 1350 so that the annular rim1316 (FIG. 13A) of the actuator tube 1314 engages the shoulder 1360 inthe metered-dose inhaler port 1350, and the container 1312 is movedtoward the neck 1330. Because the annular rim 1316 of the actuator tube1314 engages the shoulder 1360, moving the container 1312 toward theneck 1330 results in relative movement of the actuator tube 1314 towardthe container 1312, thus opening the metered valve and releasing ametered dose of medication through the actuator tube 1314. The pressureresulting from pushing the container 1312 toward the neck 1330 providessufficient sealing between the actuator tube 1314 and the shoulder 1360so that the medication travels from the actuator tube 1314 into theinner channel 1354. Because the inner channel 1354 is angled toward theoxygen reservoir bag member 1335, the medication is directed intointerior volume 1337 of the oxygen reservoir bag member 1335 where itcan disperse for inhalation by the patient.

Generally speaking, the width or diameter of the inner channel 1354 willnot be large enough to result in significant leakage of oxygen (oroxygen/air mixture) from the neck 1330 to the ambient environment, or ofambient air into the neck 1330. Optionally, an oxygen reservoir bagincluding a metered-dose inhaler port (such as oxygen reservoir bag1330) may be provided with a cap for selectively sealing themetered-dose inhaler port 1330. As shown in FIGS. 13A and 13B, theoxygen reservoir bag 1330 is provided with a cap arrangement whichincludes a cap 1380 which can be removably sealingly received in theouter channel 1356 (e.g. by a friction fit) and which is secured by aflexible attachment member 1382 to a ring 1384 which surrounds the upperend portion 1333 of the neck 1330.

Therapeutic face masks constructed in accordance with aspects of thepresent invention, such as the exemplary therapeutic face masks 210,910, can support a closed isolation system, which inhibits escape ofsupplied oxygen or oxygen/air mixture through the exhalation ports, andcan also direct exhalation to pass through a suitable filter to reducethe risk of transmitting infection by way of airborne pathogens orcontaminated water droplets entrained in the exhaled air. When asuitable filter made from an appropriate filtrate is used withtherapeutic face masks constructed in accordance with aspects of thepresent invention, a therapeutic face mask such as the therapeutic facemask 210, 910 assists in maintaining respiratory isolation of a patientduring oxygen and drug aerosol therapy, and can thereby reduce the riskof airborne infections.

Therapeutic face masks according to aspects of the present invention maycome in a variety of sizes to enable a good fit of the face-engagingportion thereof. For example, there may be provided a “large adult”size, “small adult” size, and “child” size, or other types of sizes, foreither of the exemplary therapeutic face masks 210, 910, or for othertherapeutic face masks according to aspects of the present invention.

Preferably, the face-engaging portions 212, 912 are constructed fromflexible PVC, to facilitate adjustment to individual facial features,and the connectors, such as connectors 214 and 915, and the necks, suchas necks 530, 688, 1130, 1288 of the oxygen reservoir bags 536, 1136 andnebulizers 680, 1280, are made from rigid PVC. Preferably, the PVCmaterial is a transparent or translucent PVC material. The valvediaphragms, such as diaphragms 252, 256, 932, 942, 952, are preferablymade from a suitable silicone material. All of the components oftherapeutic face masks according to aspects of the present invention arepreferably constructed from latex-free materials, so as to avoidtriggering an allergic reaction in patients having latex allergies, andare disposable for hygienic reasons. Preferably, filters used inaccordance with aspects of the present invention, such as filters 276,948, are HEPA-rated, submicron, hydrophobic filters capable ofeffectively filtering bacteria and viruses. Suitable filter materialsare available from 3M, which has a corporate headquarters address at 3MCorporate Headquarters, 3M Center, St. Paul, Minn. 55144-1000.

A single therapeutic face mask incorporating connectors according tovarious aspects of the present invention can function as a low oxygenmask, a medium oxygen mask, a high oxygen (i.e. from 30% to 90% oxygenconcentrations) mask and a nebulizer mask, obviating the need formultiple masks and thereby resulting in cost savings.

The advantages of the present invention will now be readily apparent toa person skilled in the art from the above description of a preferredembodiment thereof. Other advantages and embodiments will also be nowreadily apparent.

What is claimed is:
 1. A connector for a therapeutic face mask, theconnector having: a mask-engaging end securable to a face-engagingportion of the therapeutic face mask in fluid communication with a fluidaperture of the face-engaging portion; a treatment-receiving end; afluid passageway defined between the mask-engaging end and thetreatment-receiving end; only a single attachment mounting fordetachably sealingly receiving a treatment attachment in fluidcommunication with the fluid passageway, the attachment mounting beingdefined at the treatment-receiving end; a single inhalation valveinterposed in the fluid passageway between the mask-engaging end and thetreatment-receiving end of the connector, the inhalation valve being aone-way valve and being oriented to permit fluid flow from thetreatment-receiving end through the mask-engaging end during inhalationand to inhibit fluid flow from the mask-engaging end through thetreatment-receiving end; and an anti-asphyxia valve assembly configuredto permit fluid flow therethrough from ambient to the face-engagingportion during inhalation only when fluid flow to thetreatment-receiving end of the connector is less than inspiratory effortduring inhalation; wherein the connector includes a valve assembly, theconnector comprising: a first passage adjacent the mask-engaging end ofthe connector, from which first passage fluid can flow into theface-engaging portion and which can also receive fluid from an interiorof the face-engaging portion; a second passage adjacent thetreatment-receiving end of the connector; and the valve assembly,wherein the valve assembly comprises: the inhalation valve, theinhalation valve being associated with the first passage and the secondpassage, the inhalation valve being operable to permit fluid flow fromthe second passage to the first passage and inhibit fluid flow from thefirst passage to the second passage; an exhalation port, which includesa one-way exhalation valve associated with the first passage andoperable to permit fluid flow from the first passage to ambient and toinhibit fluid flow from ambient to the first passage; and theanti-asphyxia valve assembly, which includes a one-way anti-asphyxiavalve associated with the first passage and operable to inhibit fluidflow from the first passage to ambient and to permit fluid flow fromambient to the first passage when fluid flow into the second passage isless than inspiratory effort during inhalation; wherein the inhalationvalve comprises a disk-like diaphragm located between the first andsecond passages and movable between open and closed positions; one ofthe exhalation valve and the anti-asphyxia valve comprises an annulardiaphragm surrounding the disk-like diaphragm of the inhalation valveand movable between open and closed positions; and wherein theexhalation port comprises at least one aperture closable by theexhalation valve; the connector further comprising an annular filterhaving a central aperture, the annular filter being positioned in thevalve assembly to: filter fluid flow from the first passage through theexhalation port to ambient; and permit unfiltered fluid flow from thesecond passage to the first passage through the central aperture.
 2. Atherapeutic face mask, comprising: a face-engaging portion having afluid aperture; only a single connector, the connector having amask-engaging end and a only a single treatment-receiving end, theconnector defining a fluid passageway between the mask-engaging end andthe treatment-receiving end thereof, wherein: the mask-engaging end ofthe connector is coupled to the face-engaging portion in fluidcommunication with the fluid aperture; the connector has only a singleattachment mounting for detachably sealingly receiving a treatmentattachment in fluid communication therewith, the attachment mountingbeing defined at the treatment-receiving end of the connector; and theconnector has a single inhalation valve interposed in the fluidpassageway between the mask-engaging end and the treatment-receiving endthereof, the inhalation valve being a one-way valve and being orientedto permit fluid flow from the treatment-receiving end to themask-engaging end during inhalation and to inhibit fluid flow from themask-engaging end to the treatment-receiving end; an anti-asphyxia valveassembly configured to permit fluid flow therethrough from ambient tothe face-engaging portion during inhalation only when fluid flow to thetreatment-receiving end of the connector is less than inspiratory effortduring inhalation; and at least one valve-governed exhalation port influid communication with the face-engaging portion and positioned todefine an exhalation path from the face-engaging portion to ambientwhich bypasses the inhalation valve and which permits fluid flow fromthe face-engaging portion to ambient during exhalation and inhibitsfluid flow from ambient to the face engaging portion at least when fluidflow to the treatment-receiving end of the connector exceeds inspiratoryeffort during inhalation; wherein the connector includes a valveassembly, the connector comprising: a first passage adjacent themask-engaging end of the connector, from which first passage fluid canflow into the face-engaging portion and which can also receive fluidfrom an interior of the face-engaging portion; a second passage adjacentthe treatment-receiving end of the connector; and the valve assembly,wherein the valve assembly comprises: the inhalation valve, theinhalation valve being associated with the first passage and the secondpassage, the inhalation valve being operable to permit fluid flow fromthe second passage to the first passage and inhibit fluid flow from thefirst passage to the second passage; the exhalation port, which includesa one-way exhalation valve associated with the first passage andoperable to permit fluid flow from the first passage to ambient and toinhibit fluid flow from ambient to the first passage; and theanti-asphyxia valve assembly, which includes a one-way anti-asphyxiavalve associated with the first passage and operable to inhibit fluidflow from the first passage to ambient and to permit fluid flow fromambient to the first passage when fluid flow into the second passage isless than inspiratory effort during inhalation; wherein the inhalationvalve comprises a disk-like diaphragm located between the first andsecond passages and movable between open and closed positions; one ofthe exhalation valve and the anti-asphyxia valve comprises an annulardiaphragm surrounding the disk-like diaphragm of the inhalation valveand movable between open and closed positions; and wherein theexhalation port comprises at least one aperture closable by theexhalation valve; the therapeutic face mask further comprising anannular filter having a central aperture, the annular filter beingpositioned in the valve assembly to: filter fluid flow from the firstpassage through the exhalation port to ambient; and permit unfilteredfluid flow from the second passage to the first passage through thecentral aperture.